Positive letoff mechanism for looms



P 2, 1952 c. R. BEALL 2,609,007

POSITIVE LETOFF MECHANISM FOR LOOMS Filed May 19, 1949 3 Sheets-Sheet 2 CharlesBBea/ll ATTOR N EYS Sept. 2, 1952 c. R. BEALL 2,609,007

POSITIVE LETOFF MECHANISM FOR LOOMS Filed May 19, 1949 3 Sheets-Sheet 3 ChqrlesB.Bea/ll M M 5m ATTOR N EYS Patented Sept.;.2, 1952 p 7 2,609,007 "i os ITIvE LETOFF MECHANISM Fore LooMs Charles RossBeall, La Gran'geQGa "assignorrto West -Pqi nt Manufacturing: :iCompany; est Point, (3a., a corporationof Alabama nism for positively driving the warp beam so as-to -reg-ulatetthe deliveryiof warp yarn from the beam. t r 1 -r;-:.'Aupr-imary:object of this invention is to pro- .videi-a-iloomhaving arotatable warp beam-from which thezwarpi yarn is let ofi and delivered at a substantially constant let-off speed irrespective of y the amountwofiyarn remaining wound on the beam. a isvA-fur ther' object" of the" invention is to proavide-i-a let- -off mechanismfor" positively driving thewarp beam at' an increasing: angular velocity as the diameter of the cylindrical spool of warp yarn-wound on'the beam decreases during letoff.-.- l

Another objector the invention is to provide anwimprovedrpositive let-ofi drive'having a letspeed lcontrolled 'by the position of a follower which-contacts the cylindrical surface of the warp yarn wound on the'beam;

r'Aiurther object of the invention is to provide a-let-ofi -mechanism comp'rising an oscillating lever-"ndrivingly connected to the warp beam whereby the beam will'be-rotated at'an angular velocity directlyvproportional to the angular velocity of'xtheoscillating lever and a drive 'means for" oscillating said levee-at an angular velocity determined bythe position of a follower which maintainsicontaot with the surface of the wound yarncm .H :r r 1 a. Anotherpbject of-i the invention isto provide a noveldrive -connecticn between said oscillating lever and the warp' beam-wherebyrelative lostmot-ion may bereduced to a minimum;

,Further objectsand advantages of the present invention-willbeapparent'iromthe detailed description. and-drawings in which there is illustrated -andadescribe one particular embodiment of the invention.--=-

lln-sthendrawi-ngsu Y Figure-Lisa side elevational partial view of a loom embodying the present invention, the conventionalpart-of the loom :not being shown;

Figure 2 is an end elevational from the. right of Figure 1; 1 vFigure E isa-partial plan view;

Figure Alis -a vertical sectional View taken on the line 4"4 of Figure 1.;-

Figurefi is -a vertical sectional 'viewtaken on the. line .5 5 --of Figure 2-; a

Figure 6 is a -vertical sectional view taken" on the line 66 of Figure 3;

Figure 7 is an elevational view of the rotary ApplicationMay 19, wtase ial No; 94,175

' eolaims. (arise-408 h 2 U drivecrank as' seen from the line 1 of FigureB -Figure 8Jis a sectional view takenfo ri the line e-'-s of Figure 7; j; j

Figure 9 is a detail view of the" pawl mechanism as seen from the line 9-9 of Figure/h, V

Figure 10 i"s a sectionalview taken'on theglirie iii-I'D Of Figure' j" f I fFigure 11 shows the follower 'mcontact with the cylindrical surface of thewoun'd warp yarn; and v,

Figure 12 ais'e'ctional view taken t line i2 l2 or Figure 4. v Referring to the'ldrauiing'sand particularly to Figures 1 and 2,:"l'l and 12' indicate the two spaced upright parallel sidefrarnesojlthe loom. A bearing 'I3'isino'unted ohtheside frame H and oppositely disposedis' a bearing M mounted on' the side trams I2, conventional warp t? has'shaf ts' maria at and extending from the opposite ends thereof'aiid journalled respectively withiri 'beari'ngsliland M so asto provide arqtatable mounting foftheavarpbeam ll. As shown in Figure the-"heath" llfcomprises a hollow cylinder ll" havinga pairpf flanges m age fixedly secured atfipposite'ends otthe cylinder 'llfThe flanges l8, l9 haveannular projections as shown 'at l8"and t he shafts 15, It arefirgedly 'securedw-ithi'n these proj'ctionsof the fianges iil,

As best seen in Figure 2, a bra elz etj'a islsec'ured' to the side" frame '1 2 supports',, an; glee-.- tric meter 2 "rheibi tput' haft gzipr tn motor 21' has a gear (not in "engagementwith the gear 23 which rotates within the' gear casing 2t; 'A clutch '25 transmits the; power from" the gear23 to a'liorizo'nt'l sneeze which extends parallel totheaxisbf'the'warp'lbearnll, j y As se'enf'in Figiiiflefifthe'ndlof thel shaf tvfiii is journalled within a bearing {32 mountedon the side frame ll." fRl'elferring further to Figures fl and'8; arotarydrive crank" plate 21 is fixed to the end of theshaft 26' byfmeans of an annular flange 28"h'avin'g an opening '29 forreeeivi'nggthe view as seen a end'of the shaft 2'6 'with a pr essfi t." f H Communicating with the mete r t crank plate 2"! 'and' extending diametrically thereacross is a T-shaped slot 3 I. A crankpin 33 is integrally formed with an enlarged head portion 3 which is slidablyl" mounted within the enlarged portion of the T- shaped 'slot3l The crank pin 33 ektends from thehea'd portion 34' through thes mallerporj tion' of the'Tsshair'ied slot 3|"a'ri'd' projectsfrom thefac'e 39 cf"the*crank"plateil. The crank lected position along the length of the diametrical T-shaped slot 3|. It will thus be seen that the degree of eccentricity f the crank pin 33 with respect to the axis of the shaft 26 may be adjusted so as to obtain a desired crank throw. A washer 36 is mounted on the crank pin 33 adjacent the lock nut 35 and one end I31 of a connecting rod 31 is rotatably mounted on the crank pin 33 adjacent the washer 36. A washer 36 and locking pin 39 are mounted on the exterior end of the crank pin 33 for preventing lateral displacement of the connecting rod 31 along the axis of the crank pin 33.

As best shown in Figure 4, the side frame I I has an annular flange I 0 integral therewith and within which is rigidly secured a pin 40. A cylindrical hub member 4| is rotatably mounted on the end of pin 40. Rigidly secured to the hub 4| and extending upwardly therefrom in a plane perpendicular to the axis of pin 40 is a lever 42. It will be seen in Figure 1 that the lever 42 is preferably of arcuate shape in the form of a segment of a circle having its center coincident with the axis of the shaft 26. A series of teeth 43 ar formed on the lever 42 on the side facing the shaft 26 and crank plate 21.

As best shown in Figures 3, 4 and 12, the other end 231 of the connecting rod 31 engages the lever 42 in a manner now to be described. A tubular collar 56 surrounds the lever 42 and is freely slidable thereon. Rigidly secured to the collar 56 and extending from opposite sides thereof are pins 5| and 52. The end 231 ofconnecting rod 31 is rotatably mounted on the pin 5|" and held in assembled relation thereon by means of the washers 53, 54 and the locking pin 55.

A spring pressed detent 44 is slidably mounted on the upper edge of the connecting rod 31 adjacent the end 231 by means of pins 45 secured to the connecting rod 31 and extending within longitudinal slots 46 formed in the detent 44. A spring 48 is anchored to the connecting rod 31 by means of pin 50 and extends around the pin 49 and into a notch 41 formed in the detent 44. It will thus be seen that the spring 48 biases thedetent 44 into engagement with the teeth 43 formed on the lever 42. As shown in Figure 12, the teeth 43 depend downwardly so as to allow the detent 44 to ratchet freely over the teeth 43 when the end 231 of the connecting rod 31 is moved downwardly along the length of the lever 42 toward the axis of the pin 40.

Rigidly secured to an upper portion of the side frame II is a bracket having a bearing sleeve 6| in Figure 4, the follower 62 is substantially U- shaped and comprises vertical parallel members 63, 64 integrally formed with a horizontal member 65. The member 63 is slidable within the bearing sleeve 6| and has at the lower end thereof a yoke 66 within which is rotatably mounted a roller 61. The lower end of the member 64 is pivotally connected to the upper end of a link 69 by means of pin 68. The lower end of the link 69 is rotatably mounted on the pin 52 and held in assembled relation thereon by means of washers and a locking pin in the same manner as heretofore described with respect to the connecting rod 31 and the pin 5|.

Rigidly secured to the hub 4| and radially extending therefrom in a downward direction are two pawl supporting members 19 and 1|. A ratchet wheel 12 is rotatably mounted on the fixed pin 49 in abutting relation to the end of the hub 4|. Formed around the periphery of the ratchet for slidably mounting a follower 62. As shown Wheel 12 is a plurality of ratchet teeth 13. The lower ends of the members 10, 1| carry a plurality of pawls for engagement with the ratchet teeth 13. In the particular embodiment of the invention illustrated herein, each of the members 10, 1| has two pawls but it will be obvious that any number may b employed. As shown in Figures 9 and 10, two pawls 18 and 19 are pivotally mounted on a pin 13 fixed to the lower end of the member 16. A spring is anchored to the memher 10 at 15 and extends around the pin 13 and has a transverse portion 16 in abutment with the lower surface of the pawl 18 so as to bias the pawl 18 in a clockwise direction as viewed in Figure 9. A spring has one end rigidly secured to the upper side of thepawl 18 and has an arcuate portion which abuts against the lower side of the pawl 19 so as to bias the pawl 19 in a clockwise direction. As shown in Figure 10, the lower portion of the pawl 18, which portion is pivoted to the pin 13, comprises two parallel spaced legs 13' which form a yoke within which the lower por tion of the pawl v19 extends. As shown in Figure 5, pawls 185 and 19 are similarly mounted on the lower end of the pawl supporting member 1|.

Each of the pawls 18, 19, 19', 19' engages one of the ratchet teeth 13. It should be noted that the pawls are so positioned that only one of the pawls will be in engagement with its respective ratchet tooth .13 for any particular driving angular relationship of the hub 4| with respect to the ratchet wheel 12. For instance, it will be seen in Figure 5 that as the members 19, 1| rotate clockwise to drive the ratchet wheel 12, the pawl 19 is the only pawl in driving engagement with a ratchet tooth 13 and the other pawls 18, 1B and 19' are out of driving engagement with their respective ratchet teeth 13. Each of the pawls is positioned out of phase with respect to the other pawls. That is, assuming that there are sixty ratchet teeth on the wheel 12, the angular pitch of the teeth 13 will be six degrees. It will be obvious that if only one pawl were employed there would be a lost angular motion of the hub 4| with respect to the ratchet-Wheel 12 of six degrees. In other words, the hub 4| might rotate six degrees in the driving direction (clockwise as viewed in Figure 5) before the single pawl would drivingly engage a ratchet tooth so as to impart the rotary motion of the hub 4| to the ratchet wheel 12. However, by employing the four pawls 18, 19, 18' and 19', each out of phase with respect to the others, the lost angular motion is reduced to one-fourth, or one and one-half degrees. It will be obvious that the lost angular motion may be further reduced by providing additional phase-spaced pawls.

A bevel gear 6| is integrally formed with or otherwise rigidly secured to the ratchet wheel 12. As best seen in Figure 4, a bracket 82 is secured to the side frame H and supports a hearing 83 within which is rotatably journalled a shaft 94. Non-rotatably secured to the upper end of the shaft 84 is a bevel gear 85 inengagement with the bevel gear 8|. A worm gear 86 is non-rotatably secured to an intermediate portion of the shaft 04. The lower end of the shaft 84 is engaged by a'conventional friction clamp which latter is secured to the'side frame I by means of the bracket 81. Integrally formed with the side frame I is a bearing 89 within which is journalled a shaft 90 having a worm gear 9| secured at one end for engagement with the Worm gear 86 on the shaft 84. Non-rotatably secured to the end of the shaft 90 is a spur gear 92. A large spur gear 93 is non-rotatably secured to flange ltand shaft I5 and engages the spur'gear'S-Z: pe a n Abeamer machine (not shown) is first employed for winding the warp yarn Y onto the beam F5. The wound warp yarn'is then in the form: of a cylindrical spool composed of 7 long lengths of many threads arranged, inparallel order, As shown in this particular embodiment of the. invention, the' follower 52 is s-lidably mounted for reciprocal movement in a vertical direction and hence gravity will tend tobias the follower. 62 downwardlygwhereby the roller 61 will continue to maintain contact withthe cylindrical outer surface of the wound warp-yarn Y as said surfacerecedes toward-the axisof the beam ll during let off. of the warp yarn Y. However, it will be obvious that means "other than gravity may be used to bias the follower 62 to maintain contact with the yarn surface.-

Th'e e1ectric'1r1oto-r'2I drives the shaft- 26 at a constant speed through the gear 23 :and the clutch 25 and. thereby causes the crank plate 2-1 tor'otate at a constant angular velocity. The crank pin '33 may be fixed in a selected position within the diametric'al slot 3 I so as to obtain the desired crank throw.

The end 231 ofthe connecting rod 31 is supported by thelink 69 and followertZ at a particular position with respect to the lever 42. The spring ll} will bias the detent 4c inwardly to enage the teeth 43 of thelever 42. As the crank plate 27 rotates," an oscillatory motion will be imparted to the lever 42', the hub M and the pawl supporting members lil, H by the connecting rod 33?. The pawls constitute a one-way clutch mechanism and will'ratchet over the teeth '13 on the ratchet wheel I2 asthe members M, 42, it and H rotate in a clockwise direction as viewed in Figure 1 and will drivingly engage the ratchet wheel 72 during the counterclockwise portion of the oscillatory cycle'of said members,'thereby converting the oscillatory motion'of'the lever 42 to rotary motion of the ratchetwheel 12. The bevel gear 81 will then drive the bevel gear 35, the shaft 84 and the worm gear lit. The rotary motion of the worm gear 85 will drive theworm gear 91, the shaft Stand the spur gear 52 which latter in turn drivingly'engages the-spur gear 93 so as to cause the warp beam H to rotate and let oif'thewarp 'yarnY.

As'the cylindrical surface of the wound warp yarn Y recedes toward the axis of the beamduring let-off, the peripher'alspeed of the cylindrical spool of warp yarn would decrease if the angular velocity of the warp beam were maintained constant. Hence it is necessary to provide that the angular velocity of the warp beam ll be increased as the yarn is being let off so as to provide a substantially constant average let off, speed of the warp yarn irrespective of. the amount of yarn remaining wound on the beam ll. I

As the outer cylindrical surface of the wound yarn recedes toward the axis of the beam ll, the follower 62 will move downwardly. This movement of the follower 62 allows the end 231 of the connectingrod 31 to move downwardly along the length of the lever and toward the axis of the shaft 40. It willbe obvious that as the distance of the position of engagement of the connecting rod 31 and the lever 42 from theaxis of pin to decreases, the oscillatory amplitude and the angular velocity of the lever will increase for a given rotary crank speed. That is, the

angular velocity of the oscillating lever 42 will be inversely proportional to the distance between the positionon'the-leverAZ engaged by the connecting rod '31 and the axisof pin 40." It will also be obvious that the downward movement of the follower 62; and' hence also the downward movement of -the lever-engaging end 231 of the con necting rod3l will be directly proportional to the receding movement of the surface of the wound warp yarntoward the axis of the beam. Furthermore,- the angular velocity of the rotating ratchet "wheel 12', and'hence the angular velocity of the rotating warp beam I! will be directly proportional-to the angular velocity of the oscillating lever-42; Therefore, the angular velocity of the rotating warp beam I? will be inversely proportional to thedlstance of thesurface of wound yarn remaining on the beam 11 from the axis ofthe latter, andthe beam I! will be. accelerated as the surface of the wound yarn:recedes toward the axis of the beam 1 during let-off of the yarn. That is; thea'verage' peripheral speedof the cylindrical spoolof yarn wound on the beam ll, andhence-the let-off speed, will remain constant irrespective of thedia-meter of said spool.

It should be understood that the term constant-let-off-speed "as used inthe specification and claims refers-to the average speed and is not intended to mean that the warp yarn leaves the beam H at an instantaneous speed-which remains the same atevery instant-of loom operation, since obviously the oscillation ofthe lever dZwill im part intermittent driving impulses to the beam 11 and. the latter will accelerateand decelerate duringeaoh cycle of rotation. However, the

amount of warp yarn let off duringeach cycle of rotation of the crank plate 2? will-be substantially equal to the amount of yarn let off during any other cycle of crank plate rotation irrespective of the amount of yarn remaining wound on the beam 11, and furthermore, since the crank plate 21 rotates-at a constant speed it will be seen that although theinstantaneous let-off speed may vary during each-cycle of rotation of the crank plate-21, the average "let-off speed remains constant irrespective of the-amount of warp yarn remaining wound on the beam 11.

The'particular embodiment of the invention disclosed in this specification and-the drawings is. merely illustrative whereas the scope of the invention is delineatedin the appended claims.

Iclalm:

LA loom comprising a rotatably-mounted warp beam, a beam follower movably-mounted to maintain-contact with the-surface of warp yarn wound on the beam as'said surface recedes toward the axis of: the beam during let-offof theyarn, a lever mountedfor pivotal oscillatory movement, means 'd'rivingly connecting the lever and the beam for. converting the oscillatory movement of the lever'to 'rotarymotion of the beam whereby theangular velocity'of the beam is directly proportional to the angular velocity of the oscillating lever, a constant-speeddrive means, means for connecting said drive'means to said lever at various'positions of engagementalon'g the length of the lever'so as to oscillate said lever at an' angular velocity inversely proportional to the distance ofthe engagement position from the center of oscillation, and'means controlled by the position of the follower for varying said distance insubstantially"direct proportion'to the distance offthefoll'ower andyarn'surface from the axis '2. A loom comprising a rotatably-mounted warp beam, a beam follower movably-mounted to maintain contact with the surface of warpyarn wound on the beam as said surface recedes toward the axis of the beam during let-01f of the yarn, a lever mounted for pivotal oscillatory movement, means drivingly connecting the lever and the beam for converting the oscillatory movement of the lever to rotary motion of the beam whereby the angular velocity of the beam is directly proportional to the angular velocity of the oscillating lever, a rotary drive crank, a connecting rod having one end connected to said crank, means for connecting the other end of the connecting rod to the lever at various positions of engagement along the length of the lever so as to cause oscillation of the lever at'an angular velocity inversely proportional to the distance of the engagement position from the center of oscillation, and means controlled by the position of the follower for varying said distance in substantially direct proportion to the distance of the follower and yarn surface from the axis of the beam.

3. A loom comprising a rotatably mounted ratchet wheel, one-way-clutch pawl means warp beam, a beam follower movably-mounted to maintain contact with the surface of warp yarn wound on the beam as said surface recedes toward the axis of the beam during let-off of'the yarn, a rotatably-mounted ratchet wheel, means drivingly connecting the ratchet wheel and the beam, a hub rotatably mounted for oscillatory movement about the same axis of rotation as the ratchet wheel, one-way v clutch pawl means mounted on the hub for drivingly connecting the ratchet wheel and hub during one direction of rotation of the hub and allowing for ratcheting during the opposite direction of hub rotation, a lever secured to the hub, a drive means, means for connecting. said drive means to said lever at various positions of engagement along the length of the lever so as to oscillate said lever and hub at an angular velocity inversely proportional to the distance of the engagement position from the center of oscillation, and means controlled by the position of the follower for adjusting said distance whereby the rotary speed of the beam may be controlled by the distance of the surface of the wound warp yarn from the axis of the beam.

4. A loom comprising a rotatably-mounted warp beam, a beam follower movably-mounted to maintain contact with the surface of warp yarn wound on the beam as said surface recedes toward the axis of the beam during let-01f of the yarn, a rotatably mounted ratchet wheel, means drivingly connecting the ratchet wheel and the beam, a hub rotatably mounted for oscillatory movement about the same axis of rotation as the ratchet wheel, one-way-clutch pawl means mounted on the hub for drivingly connecting the ratchet wheel and hub during one direction of rotation of the hub and allowing for ratcheting during the opposite direction of hub rotation, a lever secured to the hub, a constant speed rotary drive crank, a connecting rod having one end connected to said crank, means for connecting the other end of the connecting rod to the lever at various positions of engagement along the length of the lever so as to cause scillation of the lever and hub at an angular velocity inversely proportional to the distance of the engagement position from the center of oscillation, and means controlled by the position of the follower for adjusting said distance whereby the rotary speed of the beam may be controlled by the distance of the surface of the wound warp yarn from the axis of the beam.

5. A loom comprising a rotatably mounted warp beam, a beam follower movably mounted to maintain contact with the surface of warp yarn wound on the beam as said surface recedes toward the axis of the beam during let-off of the yarn, a lever mounted for pivotal oscillatory movement, means drivingly connecting the lever and the beam for converting the oscillatory movement of the lever to rotary motion of the beam whereby the angular velocity of the beam is directly proportional to the angular velocity of the oscillating lever, a constant speed rotary drive crank, a connecting rod, means connecting one end of said rod to said crank at a point eccentric to the axis of rotation of the latter, the other end of the connecting rod being connected to said follower, and means mounted at said other end of the rod for engaging said lever so as to enable the connecting rod to oscillate the lever, whereby movement of the follower will control the position on the lever of the engagement of said other end of the connecting rod and thereof adjust the angular velocities of the lever and the beam in accordance with the amount of warp yarn remaining wound on the beam.

6. The combination set forth in claim 5 wherein the lever is arcuate-shaped approximately in the form of a segment of a circle having its center approximately coincident with the axis of rotation of the crank.

7. The combination set forth in claim 5 Wherein the lever has a series of teeth and said means for engaging the lever comprises a spring-pressed detent engageable with said teeth and adapted to ratchet freely thereover in a direction toward the axis of oscillation of the lever when said other end of the connecting rod is moved by the follower toward said axis of oscillation.

8. The combination set forth in claim 5 wherein said means for engaging the lever is freely movable with respect thereto in a direction along the lever toward the axis of oscillation of the lever whereby said other end of the connecting rod may be moved by the follower toward said axis of oscillation.

9. The combination set forth in claim 5 wherein said means for connecting said one end of the connecting rod to the crank comprises a crank pin rotatably secured to said one end of the rod, said crank having a slot extending radially from the axis of crank rotation, and adjustable means for securing an end of said crank pin in any selected position within said slot, whereby the throw of the crank may be adjusted to select a desired oscillatory amplitude and angular veloc ity of the lever.

CHARLES ROSS BEALL.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Germany May 13, 1885 

